Fig. 1 · D to C

interval

D minor seventh

DlowerCupperm710 half steps

Ten half steps. The interval that sits on top of a dominant seventh chord.

On the keyboard

DC
Fig. 2

What is true of it

D up a minor seventh is C: 10 half steps, and 7 letters counting both ends.

Turn it upside down — put the D on top — and it becomes a major second. The two numbers always add to nine, and the two sizes to twelve.

It is a dissonance.

Every interval on D

D → E♭minor second · dissonanceD → Emajor second · dissonanceD → Fminor third · imperfect consonanceD → F♯major third · imperfect consonanceD → Gperfect fourth · perfect consonanceD → G♯augmented fourth · dissonanceD → A♭diminished fifth · dissonanceD → Aperfect fifth · perfect consonanceD → B♭minor sixth · imperfect consonanceD → Bmajor sixth · imperfect consonanceD → C♯major seventh · dissonance

C m7C♯ m7D♭ m7D♯ m7E♭ m7E m7F m7F♯ m7all 204